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Finding the Fourth Proportional to 228.50, 315.29 and 128.92

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Solution

The fourth proportional to 228.50, 315.29 and 128.92 is: 177.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    228.50 : 315.29 = 128.92 : x
  2. Step 2: Convert to fraction form
    228.50/315.29 = 128.92/x
  3. Step 3: Cross multiply
    228.50x = 315.29 × 128.92
  4. Step 4: Simplify right side
    228.50x = 40,646.43
  5. Step 5: Solve for x
    x = 40,646.43/228.50
  6. Step 6: Final answer
    x = 177.89

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.